AFP and choriocarcinoma: Additionally, we included AFP and β-hCG (CGB), demonstrating that AFP positivity is associated with the EC signature (indicative of yolk-sac tumour components), while β-hCG positivity can be found in both expression signatures (indicative of choriocarcinoma component in EC signature and choriocarcinoma/trophoblast component in seminoma signature) (Supplementary Fig. S1C).